Which set of shapes contains members that are always similar to one another? trapezoids isosceles triangles equilateral triangles rectangles pentagons

Equilateral triangles.

Step-by-step explanation:

We know that in similar polygons, its all the corresponding angles are congruent.

Only the set of equilateral triangles contains members that are always similar( by AAA similarity criteria ) to one another as the measure of all the angles of equilateral triangle is fixed i.e. 60°.

Rest other do not have fixed measure for angles in it.

Your answer is 51

Please correct me If I am wrong

Step-by-step explanation:

Plug in 10 for x

f(x)=5(10)+1

f(10)=50+1

f(10)=51

Hope this helps :)